Comprehensive recycling method for lithium iron phosphate waste

• Main Authors: TANG HONGHUI, CHEN RUOKUI, TAN QUNYING, WANG DU, LI QIANG, QIAO YANCHAO
• Format: Patent
• Language: Chinese; English
• Published: 12.10.2018
• Subjects: BASIC ELECTRIC ELEMENTS; CHEMISTRY; ELECTRICITY; FERROUS OR NON-FERROUS ALLOYS; METALLURGY; PRETREATMENT OF RAW MATERIALS; PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSIONOF CHEMICAL INTO ELECTRICAL ENERGY; PRODUCTION AND REFINING OF METALS; TREATMENT OF ALLOYS OR NON-FERROUS METALS

The invention belongs to the technical field of lithium ion battery material recycling, and discloses a comprehensive recycling method for lithium iron phosphate waste. After being pulverized and sieved, the lithium iron phosphate waste is evenly mixed with sodium hydroxide, and in the air or oxygen atmosphere, the temperature is increased to 350-1,000 DEG C for the sintering reaction; water is added in the sintered materials for pulping, a sodium phosphate solution and lithium containing slag are obtained through filtration, and filtration is conducted after phosphoric acid is used for adjusting the pH value of the sodium phosphate solution; filter liquor is evaporated and crystallized, a sodium phosphate product is obtained, water is added in the lithium containing slag for mixing pulping, the dilute acid is used for adjusting the pH value, and a roughly-made lithium solution and iron oxide slag are obtained through filtration; and alkaline materials are used for adjusting pH of theroughly-made lithium solu